historical-speck.lore.kernel.org archive mirror
 help / color / mirror / Atom feed
From: mark gross <mgross@linux.intel.com>
To: speck@linutronix.de
Subject: [MODERATED] [PATCH 0/3] V5 more sampling fun 0
Date: Mon, 6 Apr 2020 10:52:34 -0700	[thread overview]
Message-ID: <cover.1586195554.git.mgross@linux.intel.com> (raw)

From: mark gross <mgross@linux.intel.com>
Subject: [PATCH 0/3] v5 more sampling fun

This version of the Special Register Buffer Data Sampling has been updated to
address feedback gotten.  Including:
* is based on Thomas' macro clean up for x86.
* cleanups and changes driven by review feedback.
* handles the virtualized guest case better.

---

Special Register Buffer Data Sampling is a sampling type of vulnerability that
leaks data across cores sharing the HW-RNG for vulnerable processors.

This leak is fixed by a microcode update and is enabled by default.

This new microcode serializes processor access during execution of RDRAND or
RDSEED. It ensures that the shared buffer is overwritten before it is released
for reuse.

The mitigation impacts the throughput of the RDRAND and RDSEED instructions and
latency of RT processing running on the socket while executing RDRAND or
RDSEED.  The micro benchmarks calling RDRAND many times show a slowdown.

This patch set enables kernel command line control of this mitigation and
exports vulnerability and mitigation status.
This patch set includes 3 patches:
* The first patch adds steppings to x86_cpu_id structure and related macros
* The second patch enables the command line control of the mitigation as well
  as the sysfs export of vulnerability status.
* The third patch has the Documentation/admin-guide/hw-vuln documentation for
  this issue and the control over the mitigation.


mark gross (3):
  x86/cpu: Add stepping field to x86_cpu_id structure
  x86/speculation: Special Register Buffer Data Sampling (SRBDS)
    mitigation control.
  x86/speculation: SRBDS vulnerability and mitigation documentation

 .../ABI/testing/sysfs-devices-system-cpu      |   1 +
 Documentation/admin-guide/hw-vuln/index.rst   |   2 +
 .../special-register-buffer-data-sampling.rst | 150 ++++++++++++++++++
 .../admin-guide/kernel-parameters.txt         |  20 +++
 arch/x86/include/asm/cpu_device_id.h          |  26 ++-
 arch/x86/include/asm/cpufeatures.h            |   2 +
 arch/x86/include/asm/msr-index.h              |   4 +
 arch/x86/kernel/cpu/bugs.c                    | 123 ++++++++++++++
 arch/x86/kernel/cpu/common.c                  |  61 +++++--
 arch/x86/kernel/cpu/cpu.h                     |   3 +
 arch/x86/kernel/cpu/match.c                   |   7 +-
 drivers/base/cpu.c                            |   8 +
 include/linux/mod_devicetable.h               |   2 +
 13 files changed, 393 insertions(+), 16 deletions(-)
 create mode 100644 Documentation/admin-guide/hw-vuln/special-register-buffer-data-sampling.rst

-- 
2.17.1

             reply	other threads:[~2020-04-06 18:13 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-06 17:52 mark gross [this message]
2020-01-16 22:16 ` [MODERATED] [PATCH 2/3] V5 more sampling fun 2 mark gross
2020-01-30 19:12 ` [MODERATED] [PATCH 3/3] V5 more sampling fun 3 mark gross
2020-03-17  0:56 ` [MODERATED] [PATCH 1/3] V5 more sampling fun 1 mark gross
     [not found] ` <5e8b7166.1c69fb81.4c99a.3619SMTPIN_ADDED_BROKEN@mx.google.com>
2020-04-06 18:31   ` [MODERATED] " Kees Cook
     [not found] ` <5e8b71d8.1c69fb81.64075.43abSMTPIN_ADDED_BROKEN@mx.google.com>
2020-04-06 18:34   ` [MODERATED] Re: [PATCH 2/3] V5 more sampling fun 2 Kees Cook
2020-04-06 18:37     ` Greg KH
2020-04-06 20:56       ` mark gross
2020-04-06 22:14       ` Luck, Tony
2020-04-07  7:51         ` Greg KH
2020-04-06 18:52     ` mark gross
     [not found] ` <5e8b71af.1c69fb81.d8b8.ac6bSMTPIN_ADDED_BROKEN@mx.google.com>
2020-04-06 18:34   ` [MODERATED] Re: [PATCH 3/3] V5 more sampling fun 3 Kees Cook
2020-04-06 22:07 ` [MODERATED] Re: [PATCH 2/3] V5 more sampling fun 2 Josh Poimboeuf
2020-04-07  0:34   ` mark gross
2020-04-07 12:39     ` Josh Poimboeuf
2020-04-08 20:26       ` mark gross
2020-04-08 22:14   ` mark gross
2020-04-08 22:58     ` mark gross
2020-04-07 15:17 ` Thomas Gleixner
2020-04-08 20:33   ` [MODERATED] " mark gross
2020-04-08 23:21     ` Thomas Gleixner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=cover.1586195554.git.mgross@linux.intel.com \
    --to=mgross@linux.intel.com \
    --cc=speck@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).